| # |
| # USB Core configuration |
| # |
| config USB_DEBUG |
| bool "USB verbose debug messages" |
| depends on USB |
| help |
| Say Y here if you want the USB core & hub drivers to produce a bunch |
| of debug messages to the system log. Select this if you are having a |
| problem with USB support and want to see more of what is going on. |
| |
| comment "Miscellaneous USB options" |
| depends on USB |
| |
| config USB_DEVICEFS |
| bool "USB device filesystem" |
| depends on USB |
| ---help--- |
| If you say Y here (and to "/proc file system support" in the "File |
| systems" section, above), you will get a file /proc/bus/usb/devices |
| which lists the devices currently connected to your USB bus or |
| busses, and for every connected device a file named |
| "/proc/bus/usb/xxx/yyy", where xxx is the bus number and yyy the |
| device number; the latter files can be used by user space programs |
| to talk directly to the device. These files are "virtual", meaning |
| they are generated on the fly and not stored on the hard drive. |
| |
| You may need to mount the usbfs file system to see the files, use |
| mount -t usbfs none /proc/bus/usb |
| |
| For the format of the various /proc/bus/usb/ files, please read |
| <file:Documentation/usb/proc_usb_info.txt>. |
| |
| Usbfs files can't handle Access Control Lists (ACL), which are the |
| default way to grant access to USB devices for untrusted users of a |
| desktop system. The usbfs functionality is replaced by real |
| device-nodes managed by udev. These nodes live in /dev/bus/usb and |
| are used by libusb. |
| |
| config USB_DEVICE_CLASS |
| bool "USB device class-devices (DEPRECATED)" |
| depends on USB |
| default y |
| ---help--- |
| Userspace access to USB devices is granted by device-nodes exported |
| directly from the usbdev in sysfs. Old versions of the driver |
| core and udev needed additional class devices to export device nodes. |
| |
| These additional devices are difficult to handle in userspace, if |
| information about USB interfaces must be available. One device |
| contains the device node, the other device contains the interface |
| data. Both devices are at the same level in sysfs (siblings) and one |
| can't access the other. The device node created directly by the |
| usb device is the parent device of the interface and therefore |
| easily accessible from the interface event. |
| |
| This option provides backward compatibility for libusb device |
| nodes (lsusb) when usbfs is not used, and the following udev rule |
| doesn't exist: |
| SUBSYSTEM=="usb", ACTION=="add", ENV{DEVTYPE}=="usb_device", \ |
| NAME="bus/usb/$env{BUSNUM}/$env{DEVNUM}", MODE="0644" |
| |
| config USB_DYNAMIC_MINORS |
| bool "Dynamic USB minor allocation (EXPERIMENTAL)" |
| depends on USB && EXPERIMENTAL |
| help |
| If you say Y here, the USB subsystem will use dynamic minor |
| allocation for any device that uses the USB major number. |
| This means that you can have more than 16 of a single type |
| of device (like USB printers). |
| |
| If you are unsure about this, say N here. |
| |
| config USB_SUSPEND |
| bool "USB selective suspend/resume and wakeup (EXPERIMENTAL)" |
| depends on USB && PM && EXPERIMENTAL |
| help |
| If you say Y here, you can use driver calls or the sysfs |
| "power/state" file to suspend or resume individual USB |
| peripherals. |
| |
| Also, USB "remote wakeup" signaling is supported, whereby some |
| USB devices (like keyboards and network adapters) can wake up |
| their parent hub. That wakeup cascades up the USB tree, and |
| could wake the system from states like suspend-to-RAM. |
| |
| If you are unsure about this, say N here. |
| |
| config USB_PERSIST |
| bool "USB device persistence during system suspend (DANGEROUS)" |
| depends on USB && PM && EXPERIMENTAL |
| default n |
| help |
| |
| If you say Y here and enable the "power/persist" attribute |
| for a USB device, the device's data structures will remain |
| persistent across system suspend, even if the USB bus loses |
| power. (This includes hibernation, also known as swsusp or |
| suspend-to-disk.) The devices will reappear as if by magic |
| when the system wakes up, with no need to unmount USB |
| filesystems, rmmod host-controller drivers, or do anything |
| else. |
| |
| WARNING: This option can be dangerous! |
| |
| If a USB device is replaced by another of the same type while |
| the system is asleep, there's a good chance the kernel won't |
| detect the change. Likewise if the media in a USB storage |
| device is replaced. When this happens it's almost certain to |
| cause data corruption and maybe even crash your system. |
| |
| If you are unsure, say N here. |
| |
| config USB_OTG |
| bool |
| depends on USB && EXPERIMENTAL |
| select USB_SUSPEND |
| default n |
| |
| |
| config USB_OTG_WHITELIST |
| bool "Rely on OTG Targeted Peripherals List" |
| depends on USB_OTG |
| default y |
| help |
| If you say Y here, the "otg_whitelist.h" file will be used as a |
| product whitelist, so USB peripherals not listed there will be |
| rejected during enumeration. This behavior is required by the |
| USB OTG specification for all devices not on your product's |
| "Targeted Peripherals List". |
| |
| Otherwise, peripherals not listed there will only generate a |
| warning and enumeration will continue. That's more like what |
| normal Linux-USB hosts do (other than the warning), and is |
| convenient for many stages of product development. |
| |
| config USB_OTG_BLACKLIST_HUB |
| bool "Disable external hubs" |
| depends on USB_OTG |
| help |
| If you say Y here, then Linux will refuse to enumerate |
| external hubs. OTG hosts are allowed to reduce hardware |
| and software costs by not supporting external hubs. |
| |